The present disclosure relates to programmable shims for manufacturing and assembly lines.
The advent of assembly lines has enabled rapid, mass manufacturing of products with a consequent reduction in the cost of manufactured products. Assembly lines generally include multiple operation stages and component, material or sub-assembly inputs. In mass manufacturing, a work piece such as, for example, a door, an engine, a fender, or the like, that is to undergo a series of manufacturing operations is mounted and supported on a transferring device (e.g., pallet, robots, or the like) that is transferred along the assembly line. For purposes of this disclosure it will be assumed that a pallet will be used to transfer the work piece from one station to another during manufacturing. Alternatively, a robot can be used to transfer work pieces during a manufacturing operation. A multitude of operations are performed on the work piece at various stages to produce an end product. A single assembly line can thus be used to assemble varying product types. For example, an assembly line can be configured to assemble a first engine type and then reconfigured to assemble a second, different engine type.
In the mass manufacturing of such automotive structures, it is often desirable to adjust the position of the pallet either prior to or during the manufacturing process to accommodate dimensional variations between successive work pieces. These adjustments are desirable for structures of different types and geometries but are also used to account for dimensional differences in nominally identical parts. If the pallet is not checked and adjusted as desired prior to the manufacturing operation, then the resulting work pieces may lack uniformity and may not be interchangeable. Current methods for adjusting the pallet involve the use of shims having fixed dimensions. A shim is a sheet or slab of metal, wood, plastic, or the like, that is generally used to adjust the position of the work piece by adjusting the pallet upon which the work piece is mounted. The adjustment is generally made by using manual labor, sometimes even in an iterative process, which is both time consuming and expensive. In addition errors during the adjusting process can lead to defective work pieces. It is therefore desirable to have a shim whose geometry can be altered on command, i.e., a programmable shim for adjusting the pallet that is less time consuming and offers ease of operation.